Morrisons has turned to the TV duo of Ant and Dec to help revive its flagging sales ahead of an expected dire Christmas trading update on Monday.

The grocer has signed up the two Geordies in a multimillion-pound deal also involving ITV and Simon Cowell's management firm that will see Morrisons sponsor ITV's Britain's Got Talent and Ant & Dec's Saturday Night Takeaway shows this year, as well as front a major advertising campaign.

However, the mood is likely to be anything but jokey on Monday, when Morrisons is expected to post a 2.8 per cent fall in underlying sales over the six weeks to 30 December, according to its joint house broker Jefferies. This will contrast sharply with its listed rivals Sainsbury's and Tesco, which are set to post a small rise in UK like-for-like sales. Morrisons appears to be losing market share to these and other rivals, such as the discounters Lidl and Aldi, particularly in the north of England. While this can be partly explained by Morrisons not selling food online and having only a handful of convenience stores, analysts believe its discount voucher campaign over Christmas was "disappointing".

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